W8 Inference & Effect Size

Question 1

What does inferential statistics mean?

Answer 1

• It allows us to make conclusions about the population based on samples statistics
• It takes a small sample group out of the population

Question 2

How can a mean difference of 0.097 be statistically significant?

Answer 2

• Because the sample is so big you can detect really minor differences

Question 3

What does estimating an effect size mean?

What is a benefit of being able to estimate an effect size?

Answer 3

• This indicates whether the effect matter in real life.

- A benefit of this is you can compare the effect across many other studies

Question 4

• What is effect sizes?

Answer 4

• Effect sizes are a way of standardising the magnitude of an observed effect
  Or
• It helps to establish the meaningfulness of the results

Question 5

Can you name two common effect sizes?

Answer 5

1. Correlation Coefficient (r)

2. Cohen’s D

Question 6

Can you describe a Correlation Coefficient (r)?

Answer 6

• It is an estimate of effect size (this ranges from -1 to 1 the closer to 1 the larger the effect and 0 is no effect)

Question 7

• Can you describe Cohen’s D?

- What is the calculation for Cohen’s D?

Answer 7

• When the focus is on two different means

- D = M1 - M2 / SD

Question 8

In SPSS what does the data under ‘df’ mean?

Answer 8

• ‘df’ is the total number of people involved in the study minus 2.